fs/ext2/ioctl.c

   1 /*
   2  * linux/fs/ext2/ioctl.c
   3  *
   4  * Copyright (C) 1993, 1994, 1995
   5  * Remy Card (card@masi.ibp.fr)
   6  * Laboratoire MASI - Institut Blaise Pascal
   7  * Universite Pierre et Marie Curie (Paris VI)
   8  */
   9
  10 #include "ext2.h"
  11 #include <linux/time.h>
  12 #include <linux/sched.h>
  13 #include <asm/current.h>
  14 #include <asm/uaccess.h>
  15
  16
  17 int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
  18                 unsigned long arg)
  19 {
  20         struct ext2_inode_info *ei = EXT2_I(inode);
  21         unsigned int flags;
  22
  23         ext2_debug ("cmd = %u, arg = %lu\n", cmd, arg);
  24
  25         switch (cmd) {
  26         case EXT2_IOC_GETFLAGS:
  27                 flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
  28                 return put_user(flags, (int __user *) arg);
  29         case EXT2_IOC_SETFLAGS: {
  30                 unsigned int oldflags;
  31
  32                 if (IS_RDONLY(inode))
  33                         return -EROFS;
  34
  35                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  36                         return -EACCES;
  37
  38                 if (get_user(flags, (int __user *) arg))
  39                         return -EFAULT;
  40
  41                 if (!S_ISDIR(inode->i_mode))
  42                         flags &= ~EXT2_DIRSYNC_FL;
  43
  44                 oldflags = ei->i_flags;
  45
  46                 /*
  47                  * The IMMUTABLE and APPEND_ONLY flags can only be changed by
  48                  * the relevant capability.
  49                  *
  50                  * This test looks nicer. Thanks to Pauline Middelink
  51                  */
  52                 if ((flags ^ oldflags) & (EXT2_APPEND_FL | EXT2_IMMUTABLE_FL)) {
  53                         if (!capable(CAP_LINUX_IMMUTABLE))
  54                                 return -EPERM;
  55                 }
  56
  57                 flags = flags & EXT2_FL_USER_MODIFIABLE;
  58                 flags |= oldflags & ~EXT2_FL_USER_MODIFIABLE;
  59                 ei->i_flags = flags;
  60
  61                 ext2_set_inode_flags(inode);
  62                 inode->i_ctime = CURRENT_TIME_SEC;
  63                 mark_inode_dirty(inode);
  64                 return 0;
  65         }
  66         case EXT2_IOC_GETVERSION:
  67                 return put_user(inode->i_generation, (int __user *) arg);
  68         case EXT2_IOC_SETVERSION:
  69                 if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER))
  70                         return -EPERM;
  71                 if (IS_RDONLY(inode))
  72                         return -EROFS;
  73                 if (get_user(inode->i_generation, (int __user *) arg))
  74                         return -EFAULT;
  75                 inode->i_ctime = CURRENT_TIME_SEC;
  76                 mark_inode_dirty(inode);
  77                 return 0;
  78         default:
  79                 return -ENOTTY;
  80         }
  81 }